Electric induction gasoline fuel injector



April 8, 1958 T. M. WILT 2,829,631

, ELECTRIC INDUCTION GASOLINE FUEL INJECTOR Filed Feb. '8, 1957 ATTDRNEYE United States Patent ELECTRIC INDUCTION GASOLINE FUEL INJECTORThomas M. Wilt, White Bear Lake, Minn. Application February 8,1957,Serial No. 638,972

6 Claims. (Cl. 123-139) This invention relates to fuel injection devicesof internal combustion engines, and in particular a solenoid actuatedfuel injector with the solenoid energized by induction coils around thehigh tension wires from the distributor to the spark plugs whereby fuelis supplied to the cylinders of the engine at high pressure.

The purpose of this invention is to utilize the high ten sion current ofwires carrying the current from the distributor to the spark plugs bytaking the current by induction for energizing solenoids of fuelinjectors injecting fuel under pressure to cylinders of the engine uponwhich the distributor is positioned.

In the operation of conventional internal combustion engines hightension current is supplied by a distributor to spark plugs of theengine for producing current to jump the spark gaps and this inventiontakes some of this high tension current, by induction, and suppliescurrent to solenoids for actuating high pressure injectors whereby fuelis forced under pressure into the cylinders of the engine.

The object of this invention is, therefore, to provide means forutilizing the high tension current supplied to spark plugs of aninternal combustion engine for operating a fuel injector for eachcylinder of the engine without influencing conventional operation of theengine.

Another object of the invention is to provide fuel injectors actuated byhigh tension current taken by induction from wires supplying current tospark plugs of an internal combustion engine in which the injectors areadapted to be installed in heads of motor vehicles now 1n use.

A further object of the invention is to provide means for using hightension current passing from a distributor of an internal combustionengine to spark plugs of the engine for injecting fuel under highpressure into the engine in which the device is of a simple andeconomical construction.

With these and other objects and advantages in view the inventionembodies coils positioned around wires leading from a distributor tospark plugs of an engine and mounted adjacent the distributor andsolenoid actuated plunger type injectors with the solenoids connected tothe induction coils and with plungers actuated by the solenoidspositioned to draw fuel into chambers thereof in return movements of theplungers in which the plungers are returned by springs and wherein thefuel is injected as the solenoids are energized by the plungers throughnozzles into the cylinders of the engine.

Other features and advantages of the invention will appear from thefollowing description taken in connection with the drawing, wherein:

Figure 1 is a diagrammatic view illustrating a method of connectinginduction coils around spark plug leads of an internal combustion enginewhereby the coils are connected to coils of solenoids of plungers infuel injectors for injecting fuel into cylinders of an engine underpressure.

Figure 2 is a side elevational view of a distributor of an internalcombustion engine showing induction coils positioned around spark plugleads thereof.

Figure 3 is a vertical section through a solenoid actuated fuel injectorshowing the plunger of the injector in the open or fuel receivingposition.

Figure 4 is a view similar to that shown in Fig. 3 showing the plungeractuated by the solenoid for injecting fuel into a. cylinder.

Referring now to the drawing wherein like reference characters denotecorresponding parts the improved induction coil actuated fuel injectorof internal combustion engines of this invention includes inductioncoils positioned around spark plug leads 11 of a distributor 12 andinjectors 13 having solenoid coils 14 therein with plungers 15positioned to draw fuel into chambers 16 through intake valves 17 andinject the fuel into cylinders through nozzles 18.

The solenoids 14 are mounted in inner annular recesses 19 in the bodies13 of the injectors and the plungers 15, which are slidably mounted inthe chambers 16, are provided with heads 20 that are surrounded by thecoils of the solenoids and that are urged upwardly by springs 21 whenthe solenoids are deenergized. As current is cut off through thesolenoids the springs 21 urge the heads 20 of the plungers 15 upwardlyagainst stops 22 of caps 23 which are threaded on outer surfaces of thebodies 13 and which are retained in adjusted positions with set screws24. The caps 23 are adjustable, being threaded on the bodies 13 wherebythe caps may be set to control the movements of the plungers therebyregulating the area of the chambers 16.

. The valves 17, which control the flow of fluid from supply pipes 25 tothe chambers 16 are provided with threaded shanks 26 by which they areinstalled in threaded sockets 27 in the bodies 13 and the shanks areprovided with valve seats 28 against which balls 29 are urged by springs30 in chambers 31 of the shanks and the chambers 31 are provided withopenings 32 that provide communication between the chambers 31 andchambers 16. Upon downward movements of the plungers the balls 29 areforced against the valve seats 28 and upon return movements of theplungers by the springs 21 the balls 29 are drawn away from the seats 28permitting fuel to be drawn inwardly through the tubes 29 into thechambers 16.

Also upon downward movements of the plungers 15 balls 33 are forced awayfrom seats 34 opening ports 35 whereby fuel is injected through thenozzles 18 into the cylinders.

The body 13 of each injector is provided with a threaded shank 36 thatis threaded into an opening 3'7 and the nozzle 18 is positioned in arecess. 38 in the end of the shank. The nozzle is also provided with aspring 39 that holds the ball 33 against the seat 34 except when theball is forced away from the seat by downward movement of the plunger.

In the diagram illustrated in Fig. l the arm 40 of the distributor ispositioned to engage contact points 41 of the spark plug leads 11 andthe coils 10 extended around the leads are connected by wires, such asthe wires 42 and.43 to coils of the solenoids 14 whereby an inductioncoil of one lead provides current to a solenoid of an injector of thesecond cylinder following. It will be understood that the inductioncoils may be connected to the solenoid of any suitable injector,depending upon the timing of the engine.

The coils of the solenoids are insulated from the bodies of theinjectors and plungers by sleeves A4 or by other suitable means.

It will be understood that modifications, within the scope of theappended claims, may be made in the design and arrangement of the partswithout departing from the spirit of the invention.

What is claimed is:

1. A fuel injector comprising a body having a cylindricalchamber-therein, an inlet valve mounted in the body and opening into thechamber, an outlet valve also mounted in the body and opening into thechamber, a plunger slidably mounted in the chamber, a solenoid in thebody and positioned to actuate the'plunger and an induction coil formedto be positioned around a spark plug lead of a distributor of an enginefor supplying current to the solenoid.

2. A fuel injector comprising a body having a cylindrical chambertherein, an inlet valve mounted in the body and opening into thechamber, an outlet valve also mounted in the body and opening into thechamber, a plunger slidably mounted in the chamber, a solenoid in thebody and positioned to actuate the plunger and an induction coil forsupplying current to the solenoid, said induction coil being adapted tobe positioned around a spark plug lead of a distributor of an internalcombustion engine.

3. A fuel injector comprising a body having a cylindrical chambertherein, an inlet valve mounted in the body and opening into thechamber, an outlet valve also mounted in the body and opening into thechamber, a plunger slidably mounted in the chamber, a solenoid in thebody and positioned to actuate the plunger and an induction coil forsupplying current to the solenoid, said induction coil being adapted tobe positioned around a spark plug lead of a distributor of an internalcombustion' engine, and said injector body being adapted to be threadedinto an opening in the Wall of a cylinder providing fuel supply means tothe cylinder.

4. In a fuel injector, the combination which comprises a cylinder block,a distributor, spark plugs in the cylinder block, an injector bodythreaded in the cylinder block and opening into a cylinder therein, acheck valve in the injector body and positioned to permit passage offuel from the injector body into the cylinder, said injector body havinga cylindrical chamber therein and said check valve opening into saidchamber, a fuel inlet check valve also mounted in the body and openinginto the chamber, a plunger slidably mounted in the chamber of theinjector body, a solenoid in the injector body positioned to urge theplunger to force fuel under pressure into the cylinder upon energizationthereof, resilient means for returning the plunger, and induction coilspositioned around leads of the distributor to the 4 spark plugs andconnected to the solenoids of the injector bodies.

5. In a fuel injector, the combination which comprises a cylinder block,a distributor, spark plugs in the cylinder block, an injector bodythreaded in the cylinder block and opening into a cylinder therein, acheck valve in the injector body and positioned to permit passage offuel from the injector body into the cylinder, said injector body havinga cylindrical chamber therein and said check valve opening into saidchamber, a fuel inlet check valve also mounted in the body and openinginto the chamber, a plunger slidably mounted in the chamber of theinjector body, a solenoid in the injector body positioned to urge theplunger to force fuel under pressure into the cylinder upon energizationthereof, resilient means for returning the plunger, means for adjustingthe travel of the plungers in the injector body, and induction coilspositioned around leads of the distributor to the spark plugs andconnected to the solenoids of' the injector bodies.

6. In a fuel injector, the combination which comprises an internalcombustion engine block having cylinders therein, a distributor havingcontacts therein, leads connecting the contacts of the distributor tospark plugs of the cylinders of the engine block, induction coilspositioned around the leads from the distributor to the spark plugs, aninjector body having a cylindrical chamber therein threaded in the Wallof a cylinder of the cylinder block, a plunger positioned in the chamberof the injector body, a nozzle in the passage of the injector body, avalve seatin the passage, a spring actuated valve positioned to coactwith the valve seat for closing the passage upon the return travel ofthe plunger in the cylinder, an inlet passage extended through theinjector body and opening into the chamber in which the plunger ispositioned, a spring actuated valve in the inlet connection positionedto prevent return of fluid through said inlet connection, a solenoid inthe injector body connected to one of the induction coils around thespark plug leads and positioned to drive the plunger into the chamber ofthe injector body for forcing fuel from the chamber to the passage andinto the cylinder, a spring for returning the plunger to a chargingposition, and a cap threaded on the injector body and having a stoptherein for adjusting the travel of the plunger.

1,072,712 France Mar. 17, 1954

